For decades, movies and sitcoms have presented a caricature of the sweaty-palmed, birds-and-bees conversation in which Dad stammers through a convoluted description of sex to a preadolescent child — who, it turns out, knows all of the details already. The humor arises from the tension most parents feel about discussing sex with their kids. ("What if we tell him too much?" "Will this rob him of his innocence?" "What if he starts asking about what we do?")

What isn't so funny is the reality that too many children learn about sex from everyone but their parents. Playground slang and obscenity, a distorted description of intercourse from the tough kid up the street, or worst of all, a look at some pornographic material on cable TV or the Internet often provides a child's first jarring glimpse of sex. What should be seen as the most beautiful, meaningful and private communication between a married couple becomes a freak-show curiosity. "Mom and Dad did that? More than once?!"

Efforts by public schools to correct misinformation from the street and lack of information from home often leave out a critical ingredient: the moral framework within which the facts about reproduction should be presented. Without an ethical context, sex education becomes little more than basic training in anatomy, physiology, infectious diseases and contraception.

Many churches have made laudable efforts to teach biblical principles of sexuality to their youth groups. But these important concepts are not always accompanied by accurate medical information or refusal skills. Furthermore, youth-group presentations usually begin late in the game (i.e., during the teen years) and rarely involve an on-going dialogue about this subject.

The best place for a child to learn about sexuality is at home from those who care most about him. Anyone can teach the basic facts about reproduction in an hour or two (or they can be read in any of several reference books), but you are in the best position to put this information in the proper context and give it the right perspective over a period of years. There are no cut-and-dried formulas for carrying out this assignment, but keep the following principles in mind:

Giving a child facts about reproduction, including details about intercourse, does not rob him of innocence. Innocence is a function of attitude, not information. A school-age child who understands the specifics of sex, while seeing it as an act that, in the proper context, both expresses love and begins new life, retains his innocence. But a child who knows very little about sex can already have a corrupt mind-set if he has been exposed to it in a degrading, mocking or abusive context.

If you feel squeamish or inhibited about broaching this subject with your child, reflect for a moment about your own attitudes. Do you harbor any feelings that sexual activity, even within the context of marriage, is somehow base or something that God really doesn't approve of? If you realize that this is an issue for you, some conversations with your pastor, a counselor or both may be in order. Hopefully these discussions, and perhaps a reading of the Song of Solomon and other Bible passages, will alleviate any uneasiness you might harbor regarding God's attitude toward sexuality. Books that are reliable, informative and honoring to sex, marriage and the Creator of both can also be very helpful. Two good examples are The Gift of Sex: A Guide to Sexual Fulfillment by Dr. Clifford and Joyce Penner and Intended for Pleasure by Dr. Ed and Gaye Wheat. But for many people uneasiness about sex may be rooted in life experiences, especially if they involve sexual abuse experienced during childhood, adolescence or even adulthood. It is never too late to address such issues with an individual who has training and experience in this area and can help you work toward healing.

Don't wait to tell your child everything you know about sex during a single, intense marathon session. Doing so risks either waiting until it's too late or dumping more in the child's lap than he can process. Instead, information should be released gradually during many conversations over a period of several years. (The same principle applies to any other area of life — faith, values, responsibilities, relationships, handling money and so on — in which you intend to offer guidance to your child. These subjects are too important to be confined to a single conversation.)

In many instances, you will be giving information on a need-to-know basis. Your five-year-old is probably going to want to know how the baby inside Aunt Susie is going to get out. But your child may not think to ask how the baby got there, and you don't need to broach the subject at that time. On the other hand, if you haven't yet had any discussions about reproduction with your ten-year-old, you will need to take the initiative to start some conversations. She has already heard all sorts of things on the playground and needs to hear from more reputable and mature sources.

What if your child asks you questions you can't answer? Be honest, and then do some research. You gain far more stature in your child's eyes by showing candor than by bluffing. You may not have a detailed knowledge of the intricacies of the menstrual cycle or the developmental stages of puberty, but you're never too old to learn.